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    <div style="width:150px; float:left; background:#6FF">这是左2323侧的内容</div>
    <div style="width:200px; float:right; background-color:#960">这是右侧的内容 固定宽度</div>
   
    <div style="margin-left:150px;margin-right:200px; background-color:#9F3">中间内容，自适应宽度</div>
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